The ammonite on my windowsill

Our Liparoceras was a happy ammonite that swam in the tropical sea of early Jurassic Birmingham 200 million years ago. It bobbed along upright in its shell looking for prey - which was pretty much anything it could catch: fish, other cephalopods and so forth. In fact, it looked quite like a cuttlefish stuffed into a snail shell, with all ten tentacles sticking out. It swam by jet propulsion, squirting water through its siphon, and also squirted ink at any ichthyosaur that came too close.

What was happening when our Liparoceras was alive? Pangea was breaking up and the dinosaurs were at the height of their game. There is no snow at the poles; winters are hot and wet, summers are hot and dry. The Earth spins slightly faster and the days are slightly shorter than today. Flowers haven't been invented yet, neither have fruit; instead Diplodocus browses on the leaves in a cycad forest where the ferns grow to 60 feet high. Archaeopteryx is scuttling through the undergrowth on the tail of a rat-like mammal, while high above pterosaurs circle in a thermal and laugh at them both. Insects are evolving sociality; a line of foraging ants run over the tail of an Allosaurus who is looking down the valley to where a group of scavenging Dilophosaurus are picking the meat off the carcass of its last kill, one of the young stegosaurs who got separated from the herd when they visited the river to drink yesterday morning.

Our Liparoceras knows nothing of that but it has its own problems. The shadow of a pterandon slips across the waves and it zooms for the depths. Birmingham is part of a shallow ocean, the Tethys Sea lying 15 degrees south of the equator. Liparoceras is dodging sharks, plesiosaurs, other ammonites and belemnites which either chase it away or try to catch it. It is looking for shellfish in the silts that will become the blue clay, but it is only a small ammonite and its beak is too weak to crack the oyster shells. Instead, it shoots out a tentacle and grabs a silver fish.

The most amazing thing about all this is that our Liparoceras still has its original shell and you can still see mother-of-pearl iridescence. After 200 million years it is still shining.


Liparoceras cheltiense